I am configuring a linode ubuntu server to only send valid email alerts from a python app. I setup a spf record and configured reverse dns. However my emails to my gmail account are sent to spam email, and when I look at the original messages the gmail says the spf record is "neutral" instead of pass or fail.
Are there any really good tutorials that go into everything that is needed to configure DNS (records, reverse dns, spf, hostnames, etc)?